In recent years, a touch panel system for detecting a position of an indicator on a detecting surface (for example, a finger of a user, a styrus or the like, the same shall apply hereinafter) to accept an instruction of the user is often provided on a display surface of a display device such as a portable telephone or a personal computer. Moreover, there is recently made a trial for increasing a size of the detecting surface of the touch panel system in order to provide the touch panel system on a display surface of a larger-sized display device, a white board or the like.
In the case in which the size of the detecting surface of the touch panel system is increased, it is necessary to provide a large number of elements for detecting an indicator or the like in order to detect the indicator without omission. In the case in which these elements are operated at the same time, there might be caused a problem in that a power consumption is increased, and furthermore, a detection sensitivity is deteriorated due to an occurrence of a noise or the like.
In Patent Document 1, for example, there is therefore proposed a capacitive touch panel system having an electrode arranged in vertical and horizontal directions of a detecting surface respectively in which the electrodes are detected one by one in order, and furthermore, a detection period for any of the electrodes that is closer to a position where an indicator is detected is made longer than the other electrodes.
In the touch panel system proposed in the Patent Document 1, however, it is necessary to detect the electrodes one by one in order. For this reason, a long time is required for detecting the indicator, so that a deterioration in the detection sensitivity might be caused, which is a problem.
In Patent Document 2, for example, there is proposed a capacitive touch panel system having a plurality of transmitting conductors arranged in a horizontal direction of a detecting surface and a plurality of receiving conductors arranged in a vertical direction of the detecting surface, in which a signal is applied to every predetermined number of transmitting conductors (at each predetermined interval) selectively and simultaneously and a signal generated in every predetermined number of receiving conductors (at each predetermined interval) is selectively acquired. In the touch panel system, the transmitting conductor for applying a signal and the receiving conductor for acquiring a signal are switched every predetermined time while the predetermined number of intervals are maintained respectively, thereby applying a signal to all of the transmitting conductors and acquiring a signal from all of the receiving conductors.